CVE-2026-42259Public exploitNetwork attack vector

Open redirect via backslash URL-validation bypass

Published May 7, 2026 · Updated May 7, 2026

Open redirect in affected Saltcorn releases allows remote attackers to send users to an attacker-controlled origin after login. The is_relative_url function in packages/server/routes/utils.js rejects only :/ and //, so a backslash-bearing dest value reaches the Location header and browser URL normalization changes it into a cross-origin URL. A default installation is exposed, but exploitation requires a victim to open a crafted login URL and submit valid credentials.

CVSS severity5.1
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Open redirect in affected Saltcorn releases allows remote attackers to send users to an attacker-controlled origin after login. The is_relative_url function in packages/server/routes/utils.js rejects only :/ and //, so a backslash-bearing dest value reaches the Location header and browser URL normalization changes it into a cross-origin URL. A default installation is exposed, but exploitation requires a victim to open a crafted login URL and submit valid credentials.

The record

CVE
CVE-2026-42259
Published
May 7, 2026
Updated
May 7, 2026
Vendor
Saltcorn Collective Ltd
Product
Saltcorn
Classifications
CWE-601, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 7, 2026CVE publishedPublication date reported by the CVE source.
  2. May 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.4.6
  2. Affected versionversion=>= 1.5.0-beta.0, < 1.5.6
  3. Affected versionversion=>= 1.6.0-alpha.0, < 1.6.0-beta.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Saltcorn Collective Ltd · Saltcornversion=< 1.4.6; version=>= 1.5.0-beta.0, < 1.5.6; version=>= 1.6.0-alpha.0, < 1.6.0-beta.5

Published CVSS scores

5.1GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-601URL Redirection to Untrusted Site ('Open Redirect')
T1204.001User Execution: Malicious Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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